Screw type ditch digging machine



April 5, 1955 c. FRUHLING 2,705,379

SCREW TYPE DITCH DIGGING MACHINE Filed Jan. 3, 1952 3 Sheets-Sheet 14cum. FRJHLING by: M 4% April 5, 1955 c. FRUHLING SCREW TYPE DITCHDIGGING MACHINE 5 Sheets-Sheet 2 Filed Jan. 3, 1952 Im/enzan' 0 mFRJHLING- 3y: M M,

April 5, 1955 c. FRUHLING 2,705,379

SCREW TYPE DITCH DIGGING MACH INE Filed Jan. 5, 1952 s Sheets-Sheei3United States Patent SCREW TYPE DITCH DIGGING MACHINE Curt Friihling,Hamburg, Germany, assignor to Neue Baumaschinen G. m. b. H., TegernseeObb, Germany Application January 3, 1952, Serial No. 264,748

6 Claims. (Cl. 37-81) The present invention relates to excavatingdevices, and more particularly to an excavating device for cuttingditcfiaes having a rounded bottom and inclined lateral wa s.

Excavating devices are known for digging in a continuous process ditcheshaving vertical or almost vertical side faces. Other excavating devicesoperating in a direction normal to the longitudinal extension of theditch to be excavated are also known which are capable of producing aninclined lateral face of the ditch, such excavating devices, however,are only suitable for producing the wide ditches. Shovel and bucketexcavators which produce inclined slopes in a continuous process cannotform a flat bottom of the ditch. A common disadvantage of all theseknown excavating devices is their very high weight. Also, they are notsuitable for excavating small ditches and for deepening existingditches.

It is an object of the present invention to overcome the disadvantagesof the known devices and to provide an excavating device for excavatingditches having inclined side faces and a rounded smooth bottom.

It is another object of the invention to provide an excavating devicepermitting excavation of ditches having side faces of any desiredinclination.

It is a further object of the present invention to provide an excavatingdevice having adjustable cutting members for cutting slopes havingdifferent angles.

With these objects in view the present invention mainly consists in anexcavating device comprising a rotary cutter head adapted to cut asmooth curved bottom of a ditch, and of two rotary cutting membersarranged on either side of, and above, the rotary cutter head andprovided with cutting blades which during rotation of the cuttingmembers cut the side walls of the ditch. In order to produce ditcheshaving inclined lateral faces, the rotary cutting members are pivotallymounted and may be tilted to assume positions in which they are locatedin planes extending tangentially to the curved bottom of the ditchproduced by the rotating cutter head. Radially extending blade edges ofeach cutting element out along a circle, the foremost point of which ispreferably located above the foremost pomt of the cutter head.

Behind the cutter head and secured to the same shaft, a conveyor screwis arranged for transporting the earth cut out by the cutting membersand by the cutter head to the rear where a centrifugal ejector wheelthrows it through an opening in a casing upwardly out of the ditch.

A hood covers the upper portion of the cutter head and closes the ditchtightly by engaging the faces of the excavated ditch with its edges.

The excavating unit is pulled by a vehicle moving in the direction ofexcavation and provided with a pivoted arm supporting the excavatingunit. A motor mounted on the vehicle drives the cutter head, theconveyer screw, the centrifugal ejector wheel and the cutting members.

The cutter head, the conveyer screw, and the centrifugal ejector wheelrotate preferably in the same direction and at the same rotary speed.However, it is also possible to arrange these devices on hollow shaftsand to drive the same at different rotary speeds, and in the same oropposite directions, as desired.

When the excavating device is pulled in straight direction by means ofthe vehicle on which the supporting arm for the excavating device andthe rotor for rotating Patented Apr. 5, 1955 the cutting elementsthereof are mounted, the two cutting members which are laterallyarranged of the excavating unit cut the walls of the ditch according tothe inclination to which they were adjusted. The material cut loose bythe lateral cutting members drops in front of the cutting head which isexcavating the bottom of the ditch. The earth cut by the cutter head andby the cutting members passes through the cutting elements of the cutterhead to the conveyer screw which transports the loose earth to thecentrifugal ejector wheel by which the earth is thrown out of the ditchor deposited on the side thereof. The diameter of the cuttcr head ischosen according to the width of the ditch to be excavated, and thecutter head may be exchanged, when a different diameter is required.

In the event that ditches are to be excavated, which have a widthgreater than the diameter of available cutter heads, the excavatingprocess is carried out by excavating parallel adjacent furrows whichtogether form a wide ditch.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

Fig. l is a front view of an excavating device according to the presentinvention;

Fig. 2 is a side view of the excavating unit according to the presentinvention;

Fig. 3 is a plan view of a detail of Fig. 2;

4 is a cross-sectional view taken on line A--A of 1g.

Fig. 5 is a partly cross-sectional view taken on line B- -B of Fig. 2;

Fig. 6 is a horizontal sectional view taken on line D--D of Figs. 4 and5;

Fig. 7 is a side elevation of a cutting member;

Fig. 8 is a cross-sectional view on line EE of Fig. 7;

Fig. 9 is a plan view of a detail of the cutting member taken in thedirection of the arrow F in Fig. 7;

Fig. 10 is a longitudinal sectional view of the bottom excavating andearth-conveying unit according to the present invention;

Fig. 11 is a front view of the cutter head of the bottom excavating unittaken in the direction of arrow G in Fig. 10; and

Fig. 12 is a rear view of the bottom excavating and earth-conveying unittaken in the direction of arrow H in Fig. 10.

Referring now to the drawings, Fig. 1 shows an excavating device 11having supporting members 30 which are turnably mounted on a shaft 25.Shaft 25 is mounted on a supporting member 24 which is turnably securedto the lower end of a supporting arm 19. A shaft 28 extends parallel tothe supporting arm 19 and is supported by the same. Shaft 23 drivesshaft 25 by means of bevel gears 29, and 26. The excavating device islaterally supported by the rod 22. The upper end of rod 22 is adjustablein relation to the supporting arm 19, permitting adjusting of theposition of the excavating device.

The rotatable drive shaft 28 is driven by a motor 13 which is mounted ona vehicle 14 which generally is self-propelled. A mast 15 is mounted onthe platform of the vehicle. Hoist means 18 connect the upper end of themast 15 with the outer ends of the booms 16 and 17. Booms 16 and 17 aresupported on the vehicle and mounted on a universal joint permittinghorizontal and vertical swivelling. A counterweight 23 is arranged onthe end of boom 17 in order to balance the weight of the excavatingdevice. The supporting arm 19 and the excavating unit 11 can be liftedby the boom 16 by means of the hoist 18, and also by the rope 21 passingover pulley 20 and wound on a winch (not shown) driven by motor 13.

On either side of the excavating unit 11 supporting plates 39 arearranged for supporting circular cutting members 7 which serve to shapethe lateral walls of a furrow.

Referring now to the excavating unit 11 as illustrated in Figs. 2, 10,11 and 12, a cutter head 2 comprising a milling head 32, five curvedcutting elements 9, and guiding members is fixedly mounted on a shaft 1.Also mounted on shaft 1 is a conveyer screw 3 and a centrifugal ejectorwheel 4 for throwing out the earth conveyed by the conveyer screw 3 fromthe cutter head to the rear. The cutter head 2, the conveyer screw 3 andthe wheel 4 are driven by means of the bevel gears 27 and 33 and thegears 34. Bevel gear 27 is mounted on the shaft which is driven from theshaft 28 by means of bevel gears 29 and 26. In the casing 38 of theejector wheel an opening 12 is provided for throwing out the excavatedearth.

The conveyer screw 3 is conically reduced toward the rear, while thedistance between the spirally shaped walls thereof increases in arearward direction so that the space between the convolutions of theconveyer means remains the same and the excavated earth is notcompressed while being conveyed. A hood 6 consisting of sheet metalcovers the upper portion of the cutter head 2 which constitutes awatertight closure for the bottom portion of the furrow excavated by thecutter head 2. A frusto-conically-shaped housing 5 encloses the conveyerscrew.

On either side of the excavating unit 11 a supporting plate 39 ispivotally mounted on pivoting means 39, the position of which may beadjustable. The supporting plate 39 may be secured by means of a slottedmember 42 and screws 43 in the desired inclination conforming to thedesired profile of the excavated furrow (Fig. 5).

On each supporting plate a cutting member 7 is mounted which isillustrated in Figs. 7 and 8. Each cutting member 7 comprises radiallyextending arms or spokes 36 on which cutting blades 8 are mounted whichare supported by an annular member 37 (Flg. 9).

The cutting members 7 are secured to shafts 35, which extend normal tothe supporting plates 39 and are rotatably supported on brackets 39"which project inwardly from the supporting plate 39. As illustrated inFigs. 2 and 4, the shafts 35 are driven from shaft 25 by means of chains47 and 47. Chain 47 passes over a chain wheel 46 mounted on shaft 25, achain wheel 41 and a guide chain wheel 44. Chain wheels 44, 44' aremounted on supports 45.

The chain wheels 41 and 41 are mounted on intermediate shafts 48, 48carrying bevel gears and 40' meshing with bevel gears 49, 49 which aresecured to the shaft 35, 35' of the rotary cutting members 7.

For cutting the side faces of the excavated ditch the supporting plates39 must be in a position in which the cutting members 7 are located intangential planes with respect to the curved bottom of the furrowexcavated and shaped by the cutter head 2, and in order to make aperfect adjustment possible, the pivoting means 39, and the slottedmembers 42 may be adjustably mounted. The cutting members 7 are placedin planes extending parallel with the direction of movement of thevehicle and of the cutter head, and passing through tangents on thecircle described by the outermost points of the cutter head duringrotation.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofexcavating devices differing from the types described above.

While the invention has been illustrated and described as embodied in arotary excavating unit and two lateral rotary cutting members, it is notintended to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. An excavating device, comprising in combination movable supportingmeans movable in substantially straight forward direction; a cutter headmounted on said supporting means rotatably about an axis located in avertical plane and inclined downwardly in said forward direction ofmovement, said plane being parallel to said direction of movement ofsaid supporting means, the outermost portion of said cutter headdescribing a circle during rotation; and a pair of oppositely arrangedrotary cutting members mounted on said supporting means on both sides ofsaid cutter head rotatable about axes located in a transverse plane,each cutting member having cutting edges located in a plane extendingparallel to the direction of movement of said supporting means, andpassing through a tangent on said circle, the foremost cutting edges ofsaid cutting members and of said cutter head being located in atransverse plane.

2. An excavating device, comprising in combination, movable supportingmeans movable in substantially straight forward direction; a shaftmounted on said supporting means rotatably about an axis located in avertical plane and inclined downwardly in said forward direction ofmovement, said plane being parallel to the direction of movement of saidsupporting means; a cutter head fixedly secured to the front end of saidshaft for common rotation, the outermost portions of said cutter headdescribing a circle during rotation; a conveyer screw fixedly secured tosaid shaft coaxially therewith and behind said cutter head; acentrifugal ejector wheel fixedly secured to said shaft coaxiallytherewith and behind said conveyer screw; and a pair of oppositelyarranged rotary cutting members mounted on said supporting means on bothsides of said cutter head rotatable about axes located in a transverseplane, each cutting member having radially extending cutting edgeslocated in a plane extending parallel to the direction of movement ofsaid movable supporting means, and passing through a tangent on saidcircle, the foremost cutting edges of said cutting members and of saidcutter head being located in a transverse plane.

3. An excavating device, comprising in combination, movable supportingmeans movable in substantially straight forward direction; a shaftmounted on said supporting means, downwardly inclined and having a lowerfront end, said shaft being rotatably about an axis located in avertical plane, said plane being parallel to the direction of movementof said supporting means; a cutter head fixedly secured to the front endof said shaft for common rotation, the outermost portions of said cutterhead describing a circle during rotation; a conveyer screw fixedlysecured to said shaft coaxially therewith and behind said cutter head; acentrifugal ejector wheel fixedly secured to said shaft coaxiallytherewith and behind said conveyer screw; a pair of oppositely arrangedsupporting plates pivotally mounted on said supporting means, andadapted to be located in angularly spaced planes extending parallel tothe direction of movement of said movable supporting means; and a pairof oppositely arranged rotary cutting members, each of said cuttingmembers mounted in one of said supporting plates rotatable about atransverse axis extending normal to the associated supporting plate andhaving radially extending cutting edges located in a plane extendingparallel to the direction of movement of said movable supporting means,and passing through a tangent on said circle, the foremost cutting edgesof said cutting memblers and of said cutter head being located in atransverse p ane.

4. An excavating device, comprising in combination, movable supportingmeans movable in substantially straight forward direction; a shaftmounted on said supporting means, downwardly inclined and having a lowerfront end, said shaft being rotatable about an axis located in avertical plane, said plane being parallel to the direction of movementof said supporting means; a cutter head fixedly secured to the front endof said shaft for common rotation, the outermost portions of said cutterhead describing a circle during rotation; a conveyer screw fixedlysecured to said shaft coaxially therewith and behind said cutter head;hood means secured to said movable supporting means and located abovesaid cutter head, said hood means being formed with an opening on thebottom face thereof, said hood means having edge portions extendingaround said opening and substantially horizontally arranged and adaptedto abut against the faces of a ditch excavated by said cutter head; acentrifugal ejector wheel fixedly secured to said shaft coaxiallytherewith and behind said conveyer screw; a pair of oppositely arrangedsupporting plates pivotally mounted on said supporting means, andadapted to be located in angularly spaced planes extending parellel tothe direction of movement of said movable supporting means; and a pairof oppositely arranged rotary cutting members, each of said cuttingmembers mounted in one of said supporting plates rotatable about atransverse axis extending normal to the associated supporting plate andhaving radially extending cutting edges located in a plane extendingparallel to the direction of movement of said movable supporting means,and passing through a tangent on said circle, the foremost cutting edgesof said cutting members and of said cutter head being located in atransverse plane.

5. An excavating device, comprising in combination, movable supportingmeans movable in substantially straight forward direction; a shaftmounted on said supporting means, downwardly inclined and having a lowerfront end, said shaft being rotatable about an axis located in avertical plane, said plane being parallel to the direction of movementof said supporting means; a cutter head fixedly secured to the front endof said shaft for common rotation and including a plurality of curvedcutting elements, and a plurality of earth guiding members, theoutermost portions of said cutting elements describing a circle duringrotation, the lowermost portions of said cutting elements passing duringrotation through a substantially horizontal position for cutting thebottom of a ditch; a conveyer screw fixedly secured to said shaftcoaxially therewith and behind said cutter head; hood means secured tosaid movable supporting means and located above said cutter head, saidhood means being formed with an opening on the bottom face thereof, theedge portions of said hood means extending around said opening beingsubstantially horizontally arranged and adapted to abut against thefaces of a ditch excavated by said cutter head; a centrifugal ejectorwheel fixedly secured to said shaft coaxially therewith and behind saidconveyer screw; a pair of oppositely arranged supporting platespivotally mounted on said supporting means, and adapted to be located inangularly spaced planes extending parallel to the direction of movementof said movable supporting means; and a pair of oppositely arrangedrotary cutting members, each of said cutting members mounted in one ofsaid supporting plates rotatable about a transverse axis extendingnormal to the associated supporting plate and having radially extendingcutting edges located in a plane extending parallel to the direction ofmovement of said movable supporting means, and passing through a tangenton said circle, the foremost cutting edges of said cutting members andof said cutter head being located in a transverse plane.

6. An excavating device, comprising in combination, supporting meansmovable on the ground in substantially straight forward direction andincluding a supporting arm and at least two supporting members pivotallymounted on said supporting arm; a rotary supporting shaft mounted on theend of said supporting arm and extending substantially parallel to thedirection of movement of said movable supporting means; drive means onsaid movable supporting means for driving said supporting shaft; a lowershaft mounted on said supporting members below said supporting shaft andhaving a lower front end, said lower shaft being rotatable about an axislocated in a vertical plane passing through said rotary supporting shaftand inclined downwardly in said forward direction of movement; gearmeans connecting said rotary supporting shaft and said lower shaft forcommon rotation; a cutter head fixedly secured to said lower front endof lower shaft for common rotation, the outermost portions of saidcutter head describing a circle during rotation; a pair of transversalshafts mounted on said supporting means rotatable about axes located ina transverse plane; a pair of oppositely arranged rotary cuttingmembers, each having radially extending cutting edges located in a planeextending parallel to the direction of movement of said movablesupporting means, and passing through tangents on said circle, theforemost cutting edges of said cutting members and of said cutter headbeing located in a transverse plane, each of said rotary cutting membersbeing fixedly secured to one of said transversal shafts for rotationtherewith; and transmission means operatively connecting said rotarysupporting shaft with each of said transversal shafts for driving thelatter.

References Cited in the file of this patent UNITED STATES PATENTS1,347,860 Krupp July 27, 1920 1,462,488 George July 24, 1923 1,562,842Milne Nov. 24, 1925 1,701,678 Jaeger Feb. 12, 1929 1,765,919 HeumannJune 24, 1930 2,381,017 Wandscheer Aug. 7, 1945 2,430,048 Engel et a1.Nov. 4, 1947 2,533,793 Hamlett Dec. 12, 1950 FOREIGN PATENTS 349,380Germany Mar. 3, 1922

